The effects of sewage-treatment-works effluent on epilithic bacterial and algal communities of three streams in northern england

Abstract

The responses of epilithic bacterial and algal communities to sewage-treatment-works (STW) effluent were studied in three streams in North Yorkshire, England, using both conventional microbiological techniques and the techniques of molecular genomics. Cod Beck, Thornton Beck and the River Wiske, were visited in May-June 2000 and January 2001 and the epilithic communities on submerged stones were sampled to determine chlorophyll-a, leucine assimilation, bacterial abundance, identity and abundance of microalgae, and epilithon dry and organic weights. Additionally, DNA from the epilithon of stones, collected in March-April and November 2000, was extracted, and samples were amplified using universal primers appropriate, respectively, for bacteria [Muyzer et al., 1993. Applied and Environmental Microbiology 59: 695-700] and microscopic phototrophs [Nu¨bel et al., 1997. Applied and Environmental Microbiology 63: 3327-3332] followed by DGGE (Denaturing Gradient Gel Electrophoresis). Differences in algal community composition and abundance were greater between streams than between sites upstream and downstream of the STW outfalls. DGGE banding profiles of bacterial communities revealed grouping according to stream, and not the formation of communities characteristic of downstream sites; seasonal variation was also evident. Thus the discharge of STW effluent to the streams did not bring about the development of communities that are characteristically associated with organic pollution. Changes in composition and structure of bacterial and micro-algal epilithic communities were detected, but the relatively high quality effluents had only mild effects, not altering the environments sufficiently to override the natural differences between the three streams.

Release of treated effluent into streams: A global review of ecological impacts with a consideration of its potential use for environmental flows

“…Similarly, algal biomass in German rivers was up to 8× higher in effluent‐impacted reaches than in reference reaches (Gücker, Brauns, & Pusch, 2006). Finally, total algal abundance increased with effluent inputs in two of three U.K. streams; however, the taxon richness of algae remained similar (Oliveira & Goulder, 2006). Bacillariophyceae was the dominant group and comprised >90% of the community in one of the streams.…”

Stream microbial diversity in response to environmental changes: review and synthesis of existing research

“…In complement, other environmental drivers may have a stronger effect on limiting the competitive advantage of some microbial taxa than nutrient availability. Metals concentrations ( Ancion et al, 2013 ), temperature ( Sliva and Williams, 2005 ; Zhang et al, 2012 ), OM quantity or quality ( Zoppini et al, 2010 ; Marano et al, 2011 ), hydrological factors ( Sliva and Williams, 2005 ; Zoppini et al, 2010 ), or other site-specific factors ( Oliveira and Goulder, 2006 ; Comte and del Giorgio, 2009 ; Perez et al, 2012 ; Washington et al, 2013 ) could cause stricter physiological limitations on cell success than nutrient availability. This functional redundancy and relative insensitivity of stream and river microbiota to changing nutrient concentrations helps to explain situations in which nutrient concentrations are better predictors of microbial function than microbial diversity ( Baxter et al, 2012 ).…”

Multifaceted approach for the analysis of the phototrophic microbial community in a freshwater recreational area of Xochimilco, México

“…In the monitoring of aquatic systems several methods have been successful, like for instance terminal-restriction fragment length polymorphism (T-RFLP/LH-PCR; Lepère et al, 2006;Nogales et al, 2007). However, denaturing gradient gel electrophoresis (DGGE) is perhaps the method that has increased most our understanding of community diversity in freshwater systems (Muyzer & Smalla, 1998;Casamayor et al, 2000;Demergasso et al, 2004;Unrein et al, 2005;Gucht et al, 2006;Hori et al, 2006;Oliveira & Goulder, 2006;among others).…”